A beaming Lazarevic, dressed casually in a blue hooded top, was welcomed warmly by French President Francois Hollande at a military airport outside Paris a day after his release from the hands of Al-Qaeda in the Islamic Maghreb (AQIM) was announced.

He shared an emotional embrace with his mother and sister after exiting the jet with his daughter, who had flown out the day before to Niamey -- the capital of neighbouring Niger which helped to secure his release -- to greet him.

"Life is good when you have freedom. I didn't know what it was like to be free. I had forgotten what it is like to be free. I will never forget it again," Lazarevic told reporters.

"Be careful, because freedom is dearer than anything. When you've been taken, when you're being abused, when you're lost, when you're close to death, you think more about life," he added.

Hollande said it was "an enormous joy" to see him back on French soil.

"Welcome back, Mr Lazarevic, we've been waiting for you for three years," said the president.

- 'Prisoners were freed' -

Lazarevic was the last of more than a dozen French citizens taken captive in recent years, with those held in Africa reaching a high of 15 last year. Four journalists held by Syrian jihadists were released earlier this year.

A Malian security source told AFP on condition of anonymity that Bamako had freed several AQIM prisoners "on request from Paris."

"I can tell you that men, who some may say are terrorists but to us are prisoners, were freed in exchange for the French hostage," the source said.

The negotiations were also said to involve a close associate of Iyad Ag Ghali, the head of jihadist group Ansar Dine who recently called for combat against France.

The International Federation of Human Rights (FIDH) and the Malian chapter of Amnesty International slammed the release of prisoners suspected of "grave human rights violations" in Mali.

Lazarevic was snatched by armed men in Mali on November 24, 2011 while on a business trip with fellow Frenchman Philippe Verdon in a kidnapping claimed by AQIM.

Verdon, who suffered from an ulcer and tachycardia -- an abnormally fast heartbeat -- was found shot dead last year, and those close to his family suggested he had been executed because he was weak.

Verdon's son stood alongside Lazarevic, who called him "my son" and embraced him in front of the cameras.

- 'He's doing well' -

Lazarevic was taken immediately to a military hospital for check-ups before returning to the comfort of his family, according to a diplomatic source.

"The doctor gave him a check-up on the plane and he's doing well," this source said.

In his three years in captivity, Lazarevic appeared in several AQIM videos, the most recent of which was in November in which he said he was gravely ill and believed his life was in danger.

The video spurred Lazarevic's daughter Diane to urge Hollande to obtain his release "as fast as possible... for Christmas."

Fears spiked for the safety of the tall Frenchman of Serbian origin after hiker Herve Gourdel was abducted in Algeria and beheaded in September by Islamic State-linked militants.

Lazarevic and Verdon, who worked in security and construction, were accused by AQIM of being French intelligence agents, something their families have denied.

Hollande thanked the authorities in Mali and Niger for their assistance in securing Lazarevic's release.

"This is a joy for all the French people because there are no more French hostages in any country in the world," Hollande told reporters.

"I want to deliver a clear and simple message to our compatriots who might find themselves in a high-risk zone: make sure you don't go to places where you could be taken hostage."

While the details of Lazarevic's release remain murky, France has repeatedly denied paying ransoms despite being accused by other Western nations of using back-channels to do so.

"France does not pay ransoms, nor does France engage in prisoner exchanges," Hollande said in September.